Continuous culture of normal adult mammalian hepatocytes exhibiting parenchymal functions.

Past in vitro studies of liver-cell functions have been performed on nonproliferating primary cells or serially propagated hepatic monolayers of neoplastic or fetal origin. We optimized conditions for the selective culture of adult rabbit and canine liver parenchymal cells and presently have four differentiated proliferating monolayer strains. At the 30th passage level these hepatic cultures still display the specific liver parenchymal functions of albumin and fibrinogen synthesis as well as tyrosine aminotransferase activity. Optimization of the conditions for hepatocyte culture was monitored by [3H]thymidine incorporation. Albumin and fibrinogen synthesis were measured by bioradioimmunoassay and tryosine transaminase activity by a modification of Diamondstone's assay. Albumin and fibrinogen synthesis were correlated with hepatocyte growth kinetics.

Temperature and species differences in susceptibility of kidney cell cultures to mercury toxicity.

The effect of temperature on inorganic mercury toxicity was investigated using kidney tissue culture systems. The relative susceptibility of rabbit (homeothermic) kidney to mercury intoxication was compared to that of Coho salmon (poikilothermic) kidney to mercury intoxication was compared to that of Coho salmon (poikilothermic) kidney over temperature ranges consistent with the habitat of each of the two species. It was demonstrated that susceptibility to mercury toxicity is species dependent; that is, the rabbit kidney cells tolerated higher mercury concentrations in the medium than did the fish-derived cells. Within a given species, susceptibility to mercury toxicity was temperature dependent. Decreasing the temperature increased the toxicity of mercury to cultures of rabbit kidney cells, whereas decreasing temperatures decreased the effect of mercury toxicity on the salmon kidney cells. As a consequence, fish taken from arctic waters are liable to be more toxic when introduced into mammalian food chains. Albumin was shown to act as a protective agent in vitro against inorganic mercury toxicity.